[Frontispiece: PLATE I. Scale of urinary colors, according to Vogel.]
A MANUAL OF CLINICAL DIAGNOSIS
BY JAMES CAMPBELL TODD, Ph.B., M.D.
ASSOCIATE PROFESSOR OF PATHOLOGY, DENVER AND GROSS COLLEGE OF MEDICINE
(UNIVERSITY OF DENVER); PATHOLOGIST AND CLINICAL MICROSCOPIST TO
MERCY, ST. ANTHONY'S, AND THE DENVER CITY AND COUNTY HOSPITALS
Illustrated
PHILADELPHIA AND LONDON
W. B. SAUNDERS COMPANY
1908
Copyright, 1908, by W. B. Saunders Company
PRINTED IN AMERICA
PRESS OF W. B. SAUNDERS COMPANY, PHILADELPHIA
TO MY FATHER
JOE H. TODD, M.D.
THESE PAGES ARE AFFECTIONATELY DEDICATED
PREFACE
This book aims to present a clear and concise statement of the more
important laboratory methods which have clinical value, and a brief
guide to interpretation of results. It is designed for the student and
practitioner, not for the trained laboratory worker. It had its origin
some years ago in a short set of notes which the author dictated to
his classes, and has gradually grown by the addition each year of such
matter as the year's teaching suggested. The eagerness and care with
which the students and some practitioners took these notes and used
them convinced the writer of the need of a volume of this scope.
The methods offered are practical; and as far as possible are those
which require the least complicated apparatus and the least
expenditure of time. Simplicity has been considered to be more
essential than absolute accuracy. Although in many places the reader
is given the choice of several methods to the same end, the author
believes it better to learn one method well than to learn several only
partially.
More can be learned from a good picture than from any description,
hence especial attention has been given to the illustrations, and it
is hoped that they will serve truly to _illustrate_. Practically all
the microscopic structures mentioned, all apparatus not in general
use, and many of the color reactions are shown in the pictures.
Although no credit is given in the text, the recent medical
periodicals and the various standard works have been freely consulted.
Among authors whose writings have been especially helpful may be
mentioned v. Jaksch, Boston, Simon, Wood, Emerson, Purdy, Ogden,
Ewald, Ehrlich and Lazarus, Da Costa, Cabot, Osler, Stengel, and
McFarland.
The author wishes hereby to express his indebtedness to Dr. J. A.
Wilder, Professor of Pathology in the Denver and Gross College of
Medicine, for aid in the final revision of the manuscript; and to
W. D. Engel, Ph.D., Professor of Chemistry, for suggestions in regard
to detection of drugs in the urine. He desires to acknowledge the care
with which Mr. Ira D. Cassidy has made the original drawings, and also
the uniform courtesy of W. B. Saunders Company during the preparation
of the book.
J. C. T.
DENVER, COLORADO, _July, 1908_.
CONTENTS
INTRODUCTION
Use of the Microscope . . . . . . . . . . . . . . . . . . . . . . 17
CHAPTER I
The Sputum . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Physical Examination . . . . . . . . . . . . . . . . . . . . . 25
Microscopic Examination . . . . . . . . . . . . . . . . . . . . 26
Unstained Sputum . . . . . . . . . . . . . . . . . . . . . . 26
Stained Sputum . . . . . . . . . . . . . . . . . . . . . . . 32
Sputa in Disease . . . . . . . . . . . . . . . . . . . . . . . 43
CHAPTER II
The Urine . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Physical Examination . . . . . . . . . . . . . . . . . . . . . 49
Chemic Examination . . . . . . . . . . . . . . . . . . . . . . 56
Normal Constituents . . . . . . . . . . . . . . . . . . . . . 56
Abnormal Constituents . . . . . . . . . . . . . . . . . . . . 69
Microscopic Examination . . . . . . . . . . . . . . . . . . . . 100
Unorganized Sediments . . . . . . . . . . . . . . . . . . . . 103
Organized Sediments . . . . . . . . . . . . . . . . . . . . . 113
Extraneous Structures . . . . . . . . . . . . . . . . . . . . 130
The Urine in Disease . . . . . . . . . . . . . . . . . . . . . 132
CHAPTER III
The Blood . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Hemoglobin . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Enumeration of Erythrocytes . . . . . . . . . . . . . . . . . . 149
Color Index . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Enumeration of Leukocytes . . . . . . . . . . . . . . . . . . . 156
Leukocytosis . . . . . . . . . . . . . . . . . . . . . . . . 157
Leukemia . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Enumeration of Blood-plaques . . . . . . . . . . . . . . . . . 165
Study of Stained Blood . . . . . . . . . . . . . . . . . . . . 168
Making and Staining Blood-films . . . . . . . . . . . . . . . 168
Study of Stained Films . . . . . . . . . . . . . . . . . . . 175
Blood Parasites . . . . . . . . . . . . . . . . . . . . . . . . 186
Serum Reactions . . . . . . . . . . . . . . . . . . . . . . . . 196
Tests for Recognition of Blood . . . . . . . . . . . . . . . . 202
Special Blood Pathology . . . . . . . . . . . . . . . . . . . . 203
Anemia . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Leukemia . . . . . . . . . . . . . . . . . . . . . . . . . . 208
CHAPTER IV
The Stomach . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Examination of the Gastric Contents . . . . . . . . . . . . . . 213
Obtaining the Contents . . . . . . . . . . . . . . . . . . . 214
Physical Examination . . . . . . . . . . . . . . . . . . . . 217
Chemic Examination . . . . . . . . . . . . . . . . . . . . . 218
Microscopic Examination . . . . . . . . . . . . . . . . . . . 228
The Gastric Contents in Disease . . . . . . . . . . . . . . . 230
Additional Examinations Which Give Information as to the
Condition of the Stomach . . . . . . . . . . . . . . . . . 233
CHAPTER V
The Feces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Macroscopic Examination . . . . . . . . . . . . . . . . . . . . 236
Chemic Examination . . . . . . . . . . . . . . . . . . . . . . 238
Microscopic Examination . . . . . . . . . . . . . . . . . . . . 239
CHAPTER VI
Animal Parasites . . . . . . . . . . . . . . . . . . . . . . . . 244
Protozoa . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Vermes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Arthropoda . . . . . . . . . . . . . . . . . . . . . . . . . . 259
CHAPTER VII
Miscellaneous Examinations . . . . . . . . . . . . . . . . . . . 261
Pus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Peritoneal, Pleural, and Pericardial Fluids . . . . . . . . . . 265
Cerebrospinal Fluid . . . . . . . . . . . . . . . . . . . . . . 268
Animal Inoculation . . . . . . . . . . . . . . . . . . . . . . 269
The Mouth . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
The Eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
The Ear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Parasitic Diseases of the Skin . . . . . . . . . . . . . . . . 277
Milk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Syphilitic Material . . . . . . . . . . . . . . . . . . . . . . 281
Semen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
APPENDIX
Apparatus and Reagents . . . . . . . . . . . . . . . . . . . . . 286
Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Reagents and Stains . . . . . . . . . . . . . . . . . . . . . . 288
Weights, Measures, etc., with Equivalents . . . . . . . . . . . . 292
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
{17}
A MANUAL OF CLINICAL DIAGNOSIS
INTRODUCTION
USE OF THE MICROSCOPE
There is probably no laboratory instrument whose usefulness depends so
much upon proper manipulation as the microscope, and none is so
frequently misused by beginners. Some suggestions as to its proper use
are, therefore, given at this place. It is presumed that the reader is
already familiar with its general construction (Fig. 1).
[Illustration: FIG. 1.--The microscope: 1, Eye-piece; 2, draw-tube; 3,
main tube; 4, nose-piece with objectives attached; 5, objective in
position; 6, stage; 7, substage; 8, adjustment of substage; 9, mirror;
10, coarse adjustment; 11, fine adjustment.]
Illumination.--Good work cannot be done without proper illumination.
It is difficult to lay too much stress upon this point.
The best light is that from a white cloud. {18} A northern exposure is
desirable, since direct sunlight is to be avoided. Good work can be
done at night with a Welsbach light. Ordinary gas-light and the
incandescent electric light are unsatisfactory, although the latter
gives good results when subdued with a heavily frosted globe. The
writer uses a frosted electric bulb in a dark-room lantern, and tones
the light to the proper degree for low powers by means of
frosted-glass plates which slide into the grooves which have held the
ruby and orange glasses. One of these plates is made of blue glass, to
overcome the yellow of the artificial light. It is not generally
advised to do so, but it will be found convenient to use the Abbé
condenser for all routine work. With daylight it is best to use the
plane mirror: with artificial light, the concave mirror. To obtain
best results, the light must be focused upon the object under
examination by raising or lowering the condenser.
Illumination may be either _central_ or _oblique_. Central
illumination is to be used for all routine work. To obtain this, the
mirror should be so adjusted that the light from the source selected
is reflected directly up the tube of the microscope. This is easily
done by removing the eye-piece and looking down the tube while
adjusting the mirror. The eye-piece is then replaced, and the light
reduced as much as desired by means of the diaphragm.
Oblique illumination is to be used only to bring out certain
structures more clearly after viewing them by central light: as, for
example, to show the edges of a hyaline cast by throwing one of its
sides into shadow. Oblique illumination is obtained in the more simple
instruments by swinging the mirror to one side, so that the light
enters the microscope obliquely. The more {19} complicated instruments
obtain it by means of a rack and pinion, which moves the diaphragm
laterally. Beginners frequently use oblique illumination without
recognizing it. If the light be oblique, an object in the center of
the field will appear to move from side to side when the fine
adjustment is turned back and forth.
The amount of light is even more important than its direction. It is
regulated by the diaphragm. _It is always best to use the least light
that will show the object well._ Unstained objects require very
subdued light. Beginners constantly use it too strong. Strong light
will often render semitransparent structures, as hyaline casts,
entirely invisible (Figs. 2 and 3). Stained objects, especially
bacteria, require much greater light.
[Illustration: FIG. 2.--Hyaline casts, one containing renal cells;
properly subdued illumination (from Greene's "Medical Diagnosis").]
[Illustration: FIG. 3.--Same as Fig. 2; strong illumination. The casts
are lost in the glare, and only the renal cells are seen (from
Greene's "Medical Diagnosis").]
If the reflection of the window-frame or other nearby object is seen
in the field, the condenser should be lowered a little.
Focusing.--It is always best to "focus up," which saves annoyance and
probable damage to slides and objectives. This is accomplished by
bringing the objective {20} nearer the slide than the proper focus,
and then, with the eye at the eye-piece, turning the tube up until the
object is clearly seen. _The fine adjustment should be used only to
get an exact focus with the higher power objectives after the
instrument is in approximate focus._ It should not be turned more than
one revolution.
There will be less fatigue to the eyes if both are kept open while
using the microscope, and if no effort is made to see objects which
are out of distinct focus. Fine focusing should be done with the fine
adjustment, not with the eye. An experienced microscopist keeps his
fingers almost constantly upon one or other of the focusing
adjustments. Greater skill in recognizing objects will be acquired if
the same eye be always used. To be seen most clearly, an object should
be brought to the center of the field.
Magnification.--The degree of magnification should always be expressed
in _diameters_, not _times_, which is a misleading term. The former
refers to increase of _diameter_; the latter, to increase of _area_.
The comparatively low magnification of 100 diameters is the same as
the apparently enormous magnification of 10,000 times.
Magnification may be increased--(_a_) by using a higher power
objective, which is the best way; (_b_) by using a higher eye-piece;
or (_c_) by increasing the length of tube.
Eye-pieces and Objectives.--The usual equipment consists of one- and
two-inch eye-pieces, and two-thirds, one-sixth, and one-twelfth inch
objectives. These are very satisfactory for clinical work. It is an
advantage to add a one-half-inch eye-piece for occasional use with the
two-thirds objective. The one-sixth should have an especially long
working distance, otherwise it cannot be used satisfactorily with the
Thoma-Zeiss blood-counting {21} instrument, which has a very thick
cover-glass. Such a "special one-sixth for blood work" is made by most
of the microscope manufacturers.
Objectives are "corrected" for use under certain fixed conditions, and
_they will give the best results only when used under the conditions
for which corrected_. The most important corrections are: (_a_) For
tube length; (_b_) for thickness of cover-glass; and (_c_) for the
medium between objective and cover-glass.
(_a_) The tube length with which an objective is to be used is usually
engraved upon it--in most cases it is 160 mm.
(_b_) The average No. 2 cover-glass is about the thickness for which
most objectives are corrected. Low powers do not require any
cover-glass. A cover should always be used with high powers, but its
exact thickness is more important in theory than in practice.
(_c_) The correction for the medium between objective and cover-glass
is very important. This medium may be either air or some fluid, and
the objective is hence either a "dry" or an "immersion" objective. The
immersion fluid generally used is cedar oil, which gives great optical
advantages because its index of refraction is the same as that of
crown glass. It is obvious that only objectives with very short
working distance, as the one-twelfth, can be used with an immersion
fluid.
To use an oil-immersion objective a drop of the cedar oil which is
prepared for the purpose should be placed upon the cover, and the
objective lowered into it and then brought to a focus in the usual
way. Immediately after use the oil should invariably be wiped off with
lens paper, or a soft linen handkerchief moistened with saliva.
Care of the Microscope.--The microscope is a {22} delicate instrument
and should be handled accordingly. It is so heavy that one is apt to
forget that parts of it are fragile. It seems unnecessary to say that
when there is unusual resistance to any manipulation, force should
never be used to overcome it until its cause has first been sought;
and yet it is no uncommon thing to see students, and even graduates,
push a high power objective against a microscopic preparation with
such force as to break not only the cover-glass, but even a heavy
slide.
It is most convenient to carry a microscope with the fingers grasping
the pillar and the arm which holds the tube; but since this throws a
strain upon the fine adjustment, it is safer to carry it by the base.
To bend the instrument at the joint, the force should be applied to
the pillar and never to the tube or the stage.
Lens surfaces which have been exposed to dust only should be cleaned
with a camel's-hair brush. Those which are exposed to finger-marks
should be cleaned with lens paper, or a soft linen handkerchief wet
with saliva. Particles of dirt which are seen in the field are upon
the slide, the eye-piece, or the condenser. Their location can be
determined by moving the slide, rotating the eye-piece, and lowering
the condenser.
Oil and balsam which have dried upon the lenses and resist saliva may
be removed with alcohol or xylol; but these solvents must be used
sparingly and carefully, as there is danger of softening the cement.
Care must be taken not to get any alcohol upon the brass parts, as it
will remove the lacquer. Balsam and dried oil are best removed from
the brass parts with xylol.
Measurement of Microscopic Objects.--Of the several methods, the most
convenient is the use of a {23} micrometer eye-piece. In its simplest
form this is similar to an ordinary eye-piece, but has within it a
glass disc upon which is ruled a graduated scale. When this eye-piece
is placed in the tube of the microscope, the ruled lines appear in the
microscopic field, and the size of an object is readily determined in
_terms of the divisions of this scale_. The value of these divisions
in inches or millimeters manifestly varies with different
magnifications. Their value must, therefore, be determined separately
for each objective. This is accomplished through use of a stage
micrometer--a glass slide with carefully ruled scale divided into
hundredths and thousandths of an inch, or into subdivisions of a
millimeter. The stage micrometer is placed upon the stage of the
microscope and brought into focus. From the number of divisions of the
eye-piece scale corresponding to each division of the stage micrometer
the value of the former in fractions of an inch or millimeter is
easily calculated. The counting slide of the Thoma-Zeiss hemocytometer
will answer in place of a stage micrometer, the lines which form the
sides of the small squares being one-twentieth of a millimeter apart.
Any eye-piece can be converted into a micrometer eye-piece by placing
a micrometer disc--a small circular glass plate with ruled
scale--ruled side down upon its diaphragm.
The principal microscopic objects which are measured clinically are
animal parasites and their ova and abnormal blood-corpuscles. The
metric system is used almost exclusively. For very small objects 0.001
mm. has been adopted as the unit of measurement, under the name
_micron_. It is represented by the Greek letter µ. For larger objects,
where exact measurement is not essential, the diameter of a red
blood-corpuscle (7 to 8 µ) is sometimes taken as a unit.
{24}
CHAPTER I
THE SPUTUM
Preliminary Considerations.--The morning sputum or the whole amount
for twenty-four hours should be collected for examination. In
beginning tuberculosis tubercle bacilli can often be found in that
first coughed up in the morning when they cannot be detected at any
other time of day. Sometimes, in these early cases, there are only a
few mucopurulent flakes which contain the bacilli, or only a small
purulent mass every few days, and these may easily be overlooked.
As a receptacle for the sputum a clean wide-mouthed bottle with
tightly fitting cork may be used. The patient must be particularly
cautioned against smearing any of it upon the outside of the bottle.
This is probably the chief source of danger to those who examine
sputum.
When the examination is begun, the sputum should be spread out in a
thin layer in a Petri dish, or, better, between two small plates of
glass, like photographic plates. It may then be examined with the
naked eye--best over a black background--or with a low power of the
microscope. The portions most suitable for further examination may
thus be easily selected.
After an examination the sputum must be destroyed by heat or
chemicals, and everything which has come in contact with it must be
sterilized. The utmost care must be taken not to allow any of it to
dry and become disseminated through the air.
Examination of the sputum is most conveniently {25} considered under
three heads: I. Physical examination. II. Microscopic examination.
III. Characteristics of the sputum in various diseases. Chemic
examination yields nothing of clinical importance.
I. PHYSICAL EXAMINATION
1. Quantity.--The quantity expectorated in twenty-four hours varies
greatly: it may be so slight as to be overlooked entirely in beginning
tuberculosis; and it may be as much as 1000 c.c. in bronchiectasis.
2. Color.--Since the sputum ordinarily consists of varying proportions
of mucus and pus, it may vary from a colorless, translucent mucus to
an opaque, whitish or yellow, purulent mass. A yellowish-green is
frequently seen in advanced phthisis.
A red color usually indicates the presence of blood. Bright red blood,
most commonly in streaks, is strongly suggestive of phthisis. It may
be noted very early in the disease. A rusty red sputum is the rule in
croupous pneumonia, and was at one time considered pathognomonic of
the disease. "Prune-juice" sputum is said to be characteristic of
"drunkard's pneumonia." A brown color, due to altered blood-pigment,
follows hemorrhages from the lungs.
Gray or black sputum is observed among those who work much in
coal-dust, and is occasionally seen in smokers who "inhale."
3. Consistence.--According to their consistence, sputa are usually
classified as serous, mucoid, purulent, seropurulent, mucopurulent,
etc., which names explain themselves. As a rule, the more mucus and
the less pus and serum a sputum contains, the more tenacious it is.
{26} The rusty sputum of croupous pneumonia is extremely tenacious, so
that the vessel in which it is contained may be inverted without
spilling it. The same is true of the almost purely mucoid sputum
("sputum crudum") of beginning acute bronchitis, and of that which
follows an attack of asthma. A purely serous sputum is fairly
characteristic of edema of the lungs.
II. MICROSCOPIC EXAMINATION
The portions most likely to contain structures of interest should be
very carefully selected, as already described. _The few minutes spent
in this preliminary examination will sometimes save hours of work
later._ Opaque, white or yellow particles are frequently bits of food,
but may be cheesy masses from the tonsils; small cheesy nodules,
derived from tuberculous cavities and containing many tubercle bacilli
and elastic fibers; Curschmann's spirals, or small fibrinous casts,
coiled into little balls; or shreds of mucus with great numbers of
entangled pus-corpuscles.
The sputum should always be examined, both unstained and stained.
A. UNSTAINED SPUTUM
The particle selected for examination should be transferred to a clean
slide, covered with a clean cover-glass, and examined with the
two-thirds objective, followed by the one-sixth. It is convenient to
handle the bits of sputum with a wooden toothpick, which may be burned
when done with. The platinum wire used in bacteriologic work is less
satisfactory because not usually stiff enough.
The more important structures to be seen in unstained sputum are:
elastic fibers, Curschmann's spirals, {27} Charcot-Leyden crystals,
fibrinous casts, the ray fungus of actinomycosis, and molds. Pigmented
cells, especially the so-called "heart-failure cells" (p. 43), are
also best studied without staining (Plate II, Fig. 1).
[Illustration: FIG. 4.--Elastic fibers from the sputum: _a_, Highly
magnified; _b_, alveolar arrangement, less highly magnified (after
Bizzozero).]
1. Elastic Fibers.--These are the elastic fibers of the pulmonary
substance (Fig. 4). When found in the sputum, they always indicate
destructive disease of the lungs, provided they do not come from the
food, which is a not infrequent source. They are found most commonly
in phthisis: rarely in other diseases. Advanced cases of tuberculosis
often show great numbers, and, rarely, they may be found in early
tuberculosis when the bacilli cannot be detected. In gangrene of the
lung, where they would be expected, they are frequently not found,
owing, probably, to the presence of a ferment which destroys them.
{28} The fibers should be searched for with a two-thirds objective,
although a one-sixth is needed to identify them with certainty. Under
the one-sixth they appear as slender, highly refractive fibers with
double contour and, often, curled or split ends. Frequently they are
found in alveolar arrangement, retaining the original outline of the
alveoli of the lung (Fig. 4, _b_). _Leptothrix buccalis_, which is a
normal inhabitant of the mouth, may easily be mistaken for elastic
tissue. It can be distinguished by running a little iodin solution
under the cover-glass (see p. 37).
To find elastic fibers when not abundant boil the sputum with a 10 per
cent. solution of caustic soda until it becomes fluid, add several
times its bulk of water, and centrifugalize, or allow to stand for
twenty-four hours in a conical glass. Examine the sediment
microscopically. {29} The fibers will be pale and swollen. Too long
boiling will destroy them entirely.
[Illustration: FIG. 5.--Curschmann's spirals: I., Natural size; II.
and III., enlarged: _a_, central fiber (after Curschmann).]
2. Curschmann's Spirals.--These peculiar structures are found most
frequently in bronchial asthma, of which they are fairly
characteristic. They may occasionally be met with in chronic
bronchitis and other conditions. Their nature has not been definitely
determined.
Macroscopically, they are whitish or yellow, twisted threads,
frequently coiled into little balls (Fig. 5, I.). Their length is
rarely over half an inch, though it sometimes exceeds two inches.
Under a two-thirds objective they appear as mucous threads having a
clear central fiber, about which are wound many fine fibrils (Fig. 5,
II. and III.). Leukocytes are usually present within them, and
sometimes Charcot-Leyden crystals. The central fiber is not always
present.
[Illustration: FIG. 6.--Charcot-Leyden crystals (after Riegel).]
{30} 3. Charcot-Leyden Crystals.--Of the crystals which may be found
in the sputum, the most interesting are the Charcot-Leyden crystals.
They are rarely found except in cases of bronchial asthma, and were at
one time thought to be the cause of the disease. They frequently
adhere to Curschmann spirals. Their exact nature is unknown.
They are colorless, pointed, often needle-like, octahedral crystals
(Fig. 6). Their size varies greatly, the average length being about
three or four times the diameter of a red blood-corpuscle.
Other crystals--hematoidin, cholesterin, and, most frequently, fat
needles--are common in sputum which has remained in the body for a
considerable time.
[Illustration: FIG. 7.--Fibrinous bronchial cast (Sahli).]
4. Fibrinous Casts.--These are fibrinous molds of the smaller bronchi.
Their size varies with that of the bronchi in which they are formed.
They may, rarely, {31} be three or more inches in length. When large,
they can be recognized with the naked eye by floating them out in
water; when small, a low power of the microscope must be used. They
are easily recognized from their branching, tree-like structure (Fig.
7).
Fibrinous casts are characteristic of fibrinous bronchitis, but may
also be found in diphtheria of the smaller bronchi. Very small casts
are often seen in croupous pneumonia.
[Illustration: FIG. 8.--Sputum from a case of actinomycosis; stained
(Jakob).]
5. Actinomyces Bovis (Ray-fungus).--In the sputum of pulmonary
actinomycosis and in the pus from actinomycotic lesions elsewhere
small, yellowish, "sulphur" granules can be detected with the unaided
eye. The fungus can be seen by crushing one of these granules between
slide and cover, and examining with a low power. It consists of a
network of threads having a more or less radial arrangement, those at
the periphery presenting club-shaped extremities (Fig. 8). This
organism, also called _Streptothrix actinomyces_, apparently stands
midway between the bacteria and the molds. It stains by Gram's method.
{32} Actinomycosis of the lung is rare. The clinical picture is that
of tuberculosis.
6. Molds.--The hyphæ and spores of various molds are occasionally met
with in the sputum. They are usually the result of contamination, and
have little significance. The hyphæ are rods, usually jointed or
branched (Fig. 58), and often arranged in a meshwork (mycelium); the
spores are highly refractive spheres. Both stain well with the
ordinary stains.
B. STAINED SPUTUM
Structures which are best seen in stained sputum are bacteria and
cells.
1. Bacteria.--Only those of some clinical importance will be
considered. They are: tubercle bacilli; staphylococci and
streptococci; pneumococci; bacilli of Friedländer; and influenza
bacilli.
(1) Tubercle Bacillus.--The presence of the tubercle bacillus may be
taken as positive evidence of the existence of tuberculosis somewhere
along the respiratory tract, most likely in the lung. In laryngeal
tuberculosis they are not easily found in the sputum, but can nearly
always be detected in swabs made directly from the larynx.
Recognition of the tubercle bacillus depends upon the fact that it
stains with difficulty; but that when once stained, it retains the
stain tenaciously, even when treated with a mineral acid, which
quickly removes the stain from other bacteria. The most convenient
method for general purposes is here given in detail:
* * * * *
Gabbet's Method.--(1) Spread suspicious particles thinly and evenly
upon a slide or a cover-glass held in the grasp of {33} cover-glass
forceps. Cover-glasses are easier to handle while staining. Do not
grasp a cover too near the edge or the stain will not stay on it well.
Tenacious sputum will spread better if gently warmed while spreading.
(2) Dry the film in the air.
(3) Fix in a flame; _i.e._, pass the cover-glass rather slowly, with
film side up, three times (a slide about twelve times) through the
flame of a Bunsen burner or alcohol lamp. Take care not to scorch.
Should the film be washed off during future manipulations, fixation
has been insufficient.
(4) Apply as much carbol-fuchsin as will stay on, and hold over a
flame so that it will steam for three minutes or longer, replacing the
stain as it evaporates. If the bacilli are well stained in this step,
there will be little danger of decolorizing them later.
(5) Wash the film in water.
(6) Apply Gabbet's stain to the under side of the cover-glass to
remove excess of carbol-fuchsin, and then to the film side. Allow this
to act for one-fourth to one-half minute.
(7) Wash in water.
(8) If, now, the thinner portions of the film are blue, proceed to the
next step; if they are still red, repeat steps (6) and (7) until the
red has disappeared. Too long application of Gabbet's stain will
decolorize the tubercle bacilli.
(9) Place the preparation between layers of filter-paper and dry by
rubbing with the fingers, as one would in blotting ink.
(10) Put a drop of Canada balsam upon a clean slide, place the
cover-glass film side down upon it, and examine with a one-twelfth
objective. Cedar oil or water may be used in place of balsam for
temporary preparations. Smears on slides may be examined directly with
an oil-immersion lens, no cover being necessary.
_Carbol-fuchsin_ is prepared by mixing 10 c.c. of a saturated
alcoholic solution of fuchsin with 90 c.c. of 5 per cent. aqueous
solution of phenol.
{34} _Gabbet's stain_ consists of methylene-blue, 2 gm.; 25 per cent.
sulphuric acid, 100 c.c.
Both stains can be purchased ready prepared.
* * * * *
In films stained by Gabbet's method tubercle bacilli, if present, will
be seen as slender red rods upon a blue background of mucus and cells
(Plate II, Fig. 2). They average 3 to 4 µ in length--about one-half
the diameter of a red blood-corpuscle. Beginners must be warned
against mistaking the edges of cells, or particles which have retained
the red stain, for bacilli. The appearance of the bacilli is almost
always typical, and if there seems room for doubt, the structure in
question is probably not a tubercle bacillus. They may lie singly or
in groups. They are very frequently bent and often have a beaded
appearance. It is possible that the larger, beaded bacilli indicate a
less active tuberculous process than do the smaller, uniformly stained
ones. Sometimes they are present in great numbers--thousands in a
field of the one-twelfth objective. Sometimes several cover-glasses
must be examined to find a single bacillus. At times they are so few
that none are found in stained smears, and special methods are
required to detect them. The number may bear some relation to the
severity of the disease, but this relation is by no means constant.
The mucoid sputum from an incipient case sometimes contains great
numbers, while sputum from large tuberculous cavities at times
contains very few. Failure to find them is not conclusive, though
their absence is much more significant when the sputum is purulent
than when it is mucoid.
[Illustration: PLATE II. Fig. 1.--Heart-failure cells in sputum,
containing blood-pigment, from a case of cardiac congestion of the
lungs (Jakob).
Fig. 2.--_A_, Sputum showing tubercle bacilli stained with
carbol-fuchsin and Gabbet's methylene-blue solution (obj. one-twelfth
oil-immersion); _B_, sputum of anthracosis, showing particles of
coal-dust stained with methylene-blue (obj. one-twelfth oil-immersion)
(Boston).]
When they are not found in suspicious cases, one of the following
methods should be tried:
* * * * *
(1) Take a few drams of the sputum in a test-tube, add hot {35} water,
and heat until the albumin is coagulated. Let settle for twenty-four
hours, or centrifugalize at once, and examine the sediment for
tubercle bacilli.
(2) Boil the sputum with just sufficient weak caustic soda solution to
render it fluid; neutralize with acetic acid; add several times its
volume of water; centrifugalize; and stain the sediment, adding a
little of the untreated sputum to make the smear adhere to the
cover-glass.
(3) Inoculate guinea-pigs.
* * * * *
There are a number of bacilli, called _acid-fast bacilli_, which stain
in the same way as the tubercle bacillus. Of these, the smegma
bacillus is the only one likely ever to cause confusion. It, or a
similar bacillus, is sometimes found in the sputum of gangrene of the
lung. It occurs normally about the glans penis and the clitoris, and
is often present in the urine. The method of distinguishing it from
the tubercle bacillus is given later (p. 127).
Other bacteria than the acid-fast group are stained blue by Gabbet's
method. Those most commonly found are staphylococci, streptococci, and
pneumococci. Their presence in company with the tubercle bacillus
constitutes _mixed infection_, which is much more serious than single
infection by the tubercle bacillus. It is to be remembered, however,
that a few of these bacteria may reach the sputum from the upper
air-passages. Clinically, mixed infection is evidenced by fever.
(2) Staphylococcus and Streptococcus (p. 262).--One or both of these
organisms is commonly present in company with the tubercle bacillus in
the sputum of advanced phthisis (Plate II, Fig. 2). They are often
found in bronchitis, catarrhal pneumonia, and many other conditions.
(3) Pneumococcus (Diplococcus of Fränkel).--The pneumococcus is the
causative agent in nearly all cases {36} of croupous pneumonia, and is
commonly found in large numbers in the rusty sputum of this disease.
It is sometimes met with in the sputum of catarrhal pneumonia,
bronchitis, and tuberculosis. It has been found in the saliva in
health. Pneumococci are about the size of streptococci. They are ovoid
in shape, and lie in pairs, end to end, often forming short chains.
Each is surrounded by a gelatinous capsule, which is its distinctive
feature (Fig. 9). Diplococci without capsules are common in the
sputum, but have no special significance.
[Illustration: FIG. 9.--Diplococcus pneumoniæ in the blood (Fränkel
and Pfeiffer).]
Recognition of the pneumococcus depends upon its morphology, the fact
that it is Gram-staining, and the presence of a capsule. Numerous
methods for staining capsules have been devised, but few are
satisfactory. Buerger's method is excellent. It is especially useful
with cultures upon serum media, but is applicable also to the sputum.
Smith's method usually gives good results, as does also the more
simple method of Hiss (p. 263). The sputum should be fresh--not more
than three or four hours' old.
* * * * *
{37} Buerger's Method for Capsules.--(1) Mix a few drops each of the
sputum and blood-serum on egg-albumin solution (egg-albumin, distilled
water, equal parts; shake and filter through cotton). Make thin smears
from the mixture and just as the edges begin to dry, cover with
Müller's fluid (potassium bichromate, 2.5 gm.; sodium sulphate, 1.0
gm.; water 100 c.c.) saturated with mercuric chlorid (ordinarily about
5 per cent.). Gently warm over a flame for about three seconds. This
rapidly fixes the bacteria while still living.
(2) Rinse very quickly in water.
(3) Flush once with alcohol.
(4) Apply tincture of iodin for one to two minutes.
(5) Thoroughly wash off the iodin with alcohol and dry in the air.
(6) Stain about three seconds with weak anilin-gentian-violet freshly
made up as follows: Anilin oil, 10; water, 100; shake; filter; and add
5 c.c. of a saturated alcoholic solution of gentian violet.
(7) Rinse off the stain with 2 per cent. solution of sodium chlorid,
mount in this solution, and examine with a one-twelfth objective.
Buerger suggests a very useful variation as follows: After the alcohol
wash and drying, the specimen is stained by Gram's method (p. 39),
counter-stained with aqueous solution of fuchsin, washed, and mounted
in water. The pneumococcus holds the purple stain, while all capsules
take on the pink counter-stain.
Smith's Method.--This somewhat complicated, but not difficult, method
is very useful as a routine stain for the sputum. It brings out well
all cells and all bacteria except the tubercle bacillus.
(1) Make thin smears, dry, and fix in a flame in the usual manner.
(2) Apply anilin-gentian-violet a few seconds, gently warming until
steam rises.
(3) Rinse in water.
(4) Apply Gram's iodin solution for thirty seconds.
{38} (5) Wash in 95 per cent. alcohol until the purple color ceases to
come off.
(6) Wash with equal parts of ether and absolute alcohol, or with ether
and absolute alcohol successively.
(7) Apply a saturated aqueous solution of eosin for a minute or two.
(8) Rinse off the eosin with Löffler's methylene-blue, then cover with
the methylene-blue, and heat until steam rises.
(9) Wash in water.
(10) Rinse quickly with absolute alcohol.
(11) Apply xylol a half minute or longer.
(12) Mount in balsam.
By this method organisms which stain by Gram's method (staphylococci,
streptococci, pneumococci, etc.) are purplish-black; organisms which
decolorize by Gram's method (bacilli of Friedländer, influenza
bacilli, etc.) are blue; capsules are pink; nuclei of all cells are
blue; and granules of eosinophilic cells are bright red.
_Anilin-gentian-violet_.--Ehrlich's formula is the one generally used,
but this keeps only a few weeks. Stirling's solution, which keeps much
better and seems to give equal results, is as follows: gentian-violet,
5 gm.; alcohol, 10 c.c.; anilin oil, 2 c.c.; water, 88 c.c.
_Gram's Iodin Solution_.--Iodin, 1 gm.; potassium iodid, 2 gm.; water,
300 c.c.
_Löffler's alkaline methylene-blue_ is a very generally useful stain
for bacteria. It is composed of 30 parts of a saturated alcoholic
solution of methylene-blue and 100 parts of a 1:10,000 aqueous
solution of caustic potash. It keeps indefinitely.
* * * * *
(4) Bacillus of Friedländer (Bacillus mucosus capsulatus).--In a small
percentage of cases of pneumonia, this organism is found alone or in
company with the pneumococcus. Its pathologic significance is
uncertain. It is often present in the respiratory tract under normal
conditions. Friedländer's bacilli are non-motile, {39} encapsulated
rods, sometimes arranged in short chains (Fig. 10). Very short
individuals in pairs closely resemble pneumococci, from which they are
distinguished by the fact that they are Gram-decolorizing.
[Illustration: FIG. 10.--Friedländer's bacillus in pus from pulmonary
abscess (obj. one-twelfth) (Boston).]
(5) Bacillus of Influenza.--This is the etiologic factor in true
influenza. It is present, often in large numbers, in the nasal and
bronchial secretions, and is also found in the local lesions following
influenza. Chronic infection by influenza bacilli may be mistaken
clinically for tuberculosis, and they should be searched for in all
cases of obstinate chronic bronchitis.
Their recognition depends upon the facts that they are extremely small
bacilli; that most of them lie within the pus-cells; that their ends
stain more deeply than their centers, sometimes giving the appearance
of minute diplococci; and that they are decolorized by Gram's method
of staining (Fig. 11).
They are stained blue in Gabbet's method for tubercle bacilli, but are
more certainly recognized by Smith's method or by Gram's method,
followed by Bismarck brown or fuchsin, as follows:
* * * * *
Gram's Method.--(1) Make smears, dry und fix by heat.
(2) Apply anilin-gentian-violet two to five minutes.
(3) Wash with water.
(4) Apply Gram's iodin solution one-half to two minutes.
(5) Wash in alcohol until the purple color ceases to come off.
(6) Apply a saturated aqueous or alcoholic solution of Bismarck brown
one-half to one minute, or a weak solution of fuchsin until the film
become pink. The latter {40} probably gives a better contrast stain,
but there is danger of overstaining.
(7) Wash in water, dry, and mount.
By this method Gram-staining bacteria are purple; Gram-decolorizing
bacteria and nuclei of cells are brown or red.
* * * * *
[Illustration: FIG. 11.--Bacillus of influenza; cover-glass
preparation of sputum from a case of influenza, showing the bacilli in
leukocytes; highly magnified (Pfeiffer).]
2. Cells.--These include pus-corpuscles, epithelial cells, and red
blood-corpuscles.
(1) Pus-corpuscles are present in every sputum, and at times the
sputum may consist of little else. They are the polymorphonuclear
leukocytes of the blood, and appear as rounded cells with several
nuclei or one very irregular nucleus (Fig. 8 and Plate II, Fig. 2).
They are frequently filled with granules of coal-dust and are often
much degenerated. Such coal-dust-laden leukocytes are especially
abundant in anthracosis, where angular black particles, both intra-
and extra-cellular, are often so numerous as to color the sputum
(Plate II, Fig. 2, _B_). Occasionally mononuclear leukocytes are
present.
{41} _Eosinophilic leukocytes_ are quite constantly found in large
numbers in the sputum of bronchial asthma near the time of the
paroxysm, and constitute one of the most distinctive features of the
sputum of this disease. They resemble ordinary pus-corpuscles, except
that their cytoplasm is filled with coarse granules having a marked
affinity for eosin. Large numbers of free granules, derived from
disintegrated cells, are also found (Fig. 12).
[Illustration: FIG. 12.--Sputum from a case of asthma showing
leukocytes, some containing eosinophilic granules; free eosinophilic
granules; and micrococci; stained with eosin and methylene-blue
(Jakob).]
Ordinary pus-cells are easily recognized in sputum stained by any of
the methods already given. For eosinophilic cells, some method which
includes eosin must be used. A simple method is to stain the dried and
fixed film two or three minutes with saturated solution of eosin, and
then one-half to one minute with Löffler's methylene-blue; nuclei and
bacteria will be blue, eosinophilic granules bright red.
(2) Epithelial cells may come from any part of the {42} respiratory
tract. A few are always present. They have little diagnostic value,
although a considerable excess would indicate a pathologic condition
at the site of their origin. Any of the stains mentioned above will
show them, and they can usually be identified in unstained sputum. In
general three forms are found:
(_a_) _Squamous cells_: large, flat, polygonal cells with a
comparatively small nucleus (Fig. 13, _i_). They come from the upper
air-passages, and are especially numerous in laryngitis and
pharyngitis. They are frequently studded with bacteria--most commonly
diplococci.
[Illustration: FIG. 13.--Different morphologic elements of the sputum
(unstained): _a_, _b_, _c_, Pulmonary or alveolar epithelium--_a_,
with normal lung pigment (carbon); _b_, with fat-droplets; _c_, with
myelin globules; _d_, pus-corpuscles; _e_, red blood-corpuscles; _f_,
cylindric beaker-shaped bronchial cells; _g_, free myelin globules;
_h_, ciliated epithelium of different kinds from the nose, altered by
coryza; _i_, squamous cells from the pharynx (after Bizzozero).]
(_b_) _Cylindric cells_ from the nose, trachea, and bronchi (Fig. 13,
_f_, _h_): These are not usually abundant, and, {43} as a rule, they
are not identified because much altered from their original form,
being often spheric.
(_c_) _Alveolar cells_: rather large, round, or oval cells with one or
two round nuclei (Fig. 13). Their source is presumably the pulmonary
alveoli. Like the leukocytes, they frequently contain particles of
carbon (normal lung pigment). In chronic heart disease, owing to
long-continued passive congestion, they may be filled with brown
granules of altered blood-pigment, and are then called "heart-failure
cells" (Plate II, Fig. 1). Alveolar cells commonly contain
fat-droplets and, less frequently, myelin globules. The latter are
colorless, rounded bodies, sometimes resembling fat droplets, but
often showing concentric or irregularly spiral markings (Fig. 13, _c_,
_g_). They are also found free in the sputum. They are abundant in the
scanty morning sputum of apparently healthy persons, but may be
present in any mucoid sputum.
(3) Red blood-corpuscles may be present in small numbers in almost any
sputum. When fairly constantly present in considerable numbers, they
are suggestive of phthisis. The corpuscles when fresh are shown by any
of the staining methods which include eosin. They are commonly so much
degenerated as to be unrecognizable, and often only altered
blood-pigment is left. Ordinarily, blood in the sputum is sufficiently
recognized with the naked eye.
III. SPUTA IN DISEASE
Only those conditions which give fairly characteristic sputa are
mentioned.
1. Acute Bronchitis.--There is at first a small amount of tenacious,
almost purely mucoid sputum, frequently blood-streaked. This gradually
becomes more abundant, {44} mucopurulent in character, and yellowish
or gray in color. At first the microscope shows a few leukocytes and
alveolar and bronchial cells; later, the leukocytes become more
numerous. Bacteria are not usually abundant.
2. Chronic Bronchitis.--The sputum is usually abundant, mucopurulent,
and yellowish or yellowish-green in color. Nummular masses--circular,
"coin-like" discs which sink in water--may be seen. Microscopically,
there are great numbers of leukocytes, often much degenerated.
Epithelium is not abundant. Bacteria of various kinds, especially
staphylococci, are usually numerous.
In fibrinous bronchitis there are found, in addition, fibrinous casts,
usually of medium size.
In the chronic bronchitis accompanying long-continued passive
congestion of the lungs, as in poorly compensated heart disease, the
sputum may assume a rusty brown color, owing to presence of large
numbers of the "heart-failure cells" previously mentioned.
3. Bronchiectasis.--The sputum is very abundant at intervals,
sometimes as high as a liter in twenty-four hours, and has a very
offensive odor when the cavity is large. It is thinner than that of
chronic bronchitis, and upon standing separates into three layers of
pus, mucus, and frothy serum. It contains great numbers of
miscellaneous bacteria.
4. Gangrene of the Lung.--The sputum is abundant, fluid, very
offensive, and brownish in color. It separates into three layers upon
standing--a brown deposit, a clear fluid, and a frothy layer.
Microscopically, few cells of any kind are found. Bacteria are
extremely numerous; among them may sometimes be found an acid-fast
bacillus probably identical with the smegma bacillus. As before {45}
stated, elastic fibers are less common than would be expected.
5. Pulmonary Edema.--Here there is an abundant, watery, frothy sputum,
varying from faintly yellow or pink to dark-brown in color; a few
leukocytes and epithelial cells and varying numbers of red
blood-corpuscles are found with the microscope.
6. Bronchial Asthma.--The sputum during and following an attack is
scanty and very tenacious. Most characteristic is the presence of
Curschmann's spirals, Charcot-Leyden crystals, and eosinophilic
leukocytes.
7. Croupous Pneumonia.--Characteristic of this disease is a scanty,
rusty red, very tenacious sputum containing red corpuscles or altered
blood-pigment, leukocytes, epithelial cells, usually many pneumococci,
and often very small fibrinous casts. This sputum is seen during the
stage of red hepatization. During resolution the sputum assumes the
appearance of that of chronic bronchitis. When pneumonia occurs during
the course of a chronic bronchitis, the characteristic rusty red
sputum may not appear.
8. Pulmonary Tuberculosis.--The sputum is variable. In the earliest
stages it may be scanty and almost purely mucoid, with an occasional
yellow flake, or there may be only a very small mucopurulent mass.
When the quantity is very small there may be no cough, the sputum
reaching the larynx by action of the bronchial cilia. This is not well
enough recognized by practitioners. A careful inspection of all the
sputum brought up by the patient on several successive days, and a
microscopic examination of all yellow portions, will not infrequently
establish a diagnosis of tuberculosis when physical signs are
negative. {46} Tubercle bacilli will sometimes be found in large
numbers at this stage. Blood-streaked sputum is strongly suggestive of
tuberculosis, and is more common in the early stages than later.
The sputum of more advanced cases resembles that of chronic
bronchitis, with the addition of tubercle bacilli and elastic fibers.
Caseous particles containing immense numbers of the bacilli are
common. Far-advanced cases with large cavities often show rather firm,
spheric or ovoid masses of thick pus in a thin fluid--the so-called
"globular sputum." These globular masses usually contain many tubercle
bacilli.
{47}